This Shared Instrumentation Grant will enable the installation and implementation of a Robotic Arm System for precise targeting of image- guided noninvasive brain stimulation via transcranial magnetic stimulation (TMS) for the study of brain behavior relationships, pathophysiology of brain-based disorders, and intervention development trials. Noninvasive brain stimulation via TMS has become a valuable method, in combination with structural and functional neuroimaging, to experimentally test brain-behavior relationships and to test the causal role of brain networks hypothesized to underlie core aspects of cognitive function. TMS has also demonstrated clinical utility, receiving FDA approval in October of 2008 for the treatment of major depression. While these developments have been exciting, the value of focal brain stimulation via TMS hinges upon the precision with which the intervention can be targeted. Frameless stereotaxy systems exist to navigate the TMS coil based upon individual anatomy as visualized via MRI, and individual functional anatomy as defined by fMRI or PET overlaid upon the structural scan. These innovations have increased effect sizes for both basic and clinical studies. However, frameless stereotaxy systems are limited in that they require rigid head fixation, representing a significant problem for subjects with movement disorders or abnormal repetitive behaviors, and for studies requiring verbal responses from subjects that makes the use of a chin rest impractical. Furthermore, those systems are subject to human error in coil positioning and in maintenance of coil position over extended periods of testing. Now, robotic technology has removed the necessity for rigid head fixation, and enables real-time tracking of head movements with a robotic arm that moves the coil in tandem with the subject's head. Robotic TMS coil placement improves the precision of TMS positioning, thereby it can be expected to improve effect sizes, permitting investigators to test hypotheses with smaller sample sizes and to perform mapping studies with higher spatial resolution. It also enables the study of subjects and paradigms where rigid head fixation is not possible or is impractical. The Noninvasive Neuromodulation Neuroscience Laboratory, led by Dr. Bruce Luber, is uniquely poised to implement this state-of-the-art technology and make it available as a core resource to support NIH fund investigators in their studies. The Laboratory is supported by the considerable expertise in TMS studies of the Columbia Brain Stimulation and Therapeutic Modulation Division. Engineering support will be provided by the TMS Technology Development Laboratory, and medical supervision and infrastructure for TMS studies will be provided by the Brain Behavior Clinic. This program already has a large number of active TMS studies which stand to benefit from this new shared resource, and strong institutional support is being provided by the Columbia Department of Psychiatry to facilitate the optimal utility and scientific impact of this core facility.